W wallqvist



Jan. 29, 1963 s. H. WALLQVIST ETAL 3,075,697

LOCKING DEVICE FOR THE ADJUSTMENT OF DIGIT INVENTORS WHEELS AND THE LIKE Filed May 11, 1961 lo e! 4 Q nite Fasten-ted Jan. 29, i353 3,075,67 DEVHQE FGR THE ADEUSTh/llhi'l 6F DlGiT WHEELS AND THE LIKE Sven Hiikau Wallqvist, Halrnstad, and Bengt A. Blink, Getinge, Sweden, asslgnors to fielder; Aktieholag, Hairnstad, dweden Filed May 11, 1961, Ser. No. 169,349 Claims priority, application Sweden May 1.1, 196i 3 Claims. (Cl. 235-1) The present invention refers to a locking device to bring about a selectable adjustment of the angular position of the digit drum or digit disk relatively to the driving wheels thereof in a calculating apparatus. It is, particularly in taximeters, desirable to be able readily to shift the setting of the basic amount of the amountindicating digit Wheels in changing the basic or starting fare. The present invention refers to an arrangement, wherein this may be carried into effect in a simple manner and wherein without the aid of a special tool an unauthorized adjustment is rendered difficult.

A locking device according to the invention comprises a digit drum or digit disk and a feeding wheel with a Zeroizing heart coaxially arranged therewith, wherein the digit drum and the feeding wheel are rotatably mounted relatively to one another and wherein locking members are adapted to fix the digit drum and the zeroizing heart in definite angular positions relatively to each other, and the invention is principally characterized in that the locking members consist of pins which are axially displacesble in the hub of the feeding wheel, in connection with which a disk carrying the digit drum is mounted in the hub and provided with apertures to cooperate with the pins, said apertures being accessible from the outside of the disk.

The invention will be explained more closely with reference to the accompanying drawing, wherein FIG. 1 illustrates a digit wheel arrangement according to the invention viewed in perspective with a tool adapted to actuate the locking members, and wherein FIG. 2 shows the arrangement viewed partly in section and likewise in perspective.

The contrivance shown consists of a digit drum 1 of a gear wheel 2 driving the drum and coaxially arranged with said digit drum. The gear wheel is provided with a hub 3 having an aperture 4 for the shaft of the calculating apparatus (not shown). The hub 3 is rigidly connected to a bushing 5, which is secured to the gear wheel by means of rivets 6. The hub 3 proiects somewhat outside of the gear wheel 2 to form a centered support for a zeroizing cam disk or a so-called zeroizing heart 7 arranged on the outside of the gear wheel. The pposite end of the hub 3 is provided with a flange 3 at a distance from the end surface of the bushing 5. A disk 53 is rotatably mounted about the hub 3 in the space between the flange 3 and the busning 5. Said disk 9 is connected to a flange '10 on the digit drum fl. The disk 9 consequently carries the digit drum 1. Through the latter arrangement the digit drum 1 and the gear wheel 2 are adapted to be rotated relatively to each other. At a point of the peripheral edge, the disk i carries members 11 to bring about a so-called tens transfer to the adjacent digit wheel.

Provi ed in the bushing are two diametrically arranged bores 12, through the bottoms of which the rivets 6 are arranged. The bores extend in parallel to the aperture 4 through the bushing. Axially movable in the bores are pins 13, which are actuated in a direction toward the disk 9 by means of coil springs 14 acting between the bottom portions of the bores 12 and the inner lateral surface of the pins 13. The outer, free portion 15 of the pins 13 has a smaller diameter, and these pins are adapted to cooperate with pairs of apertures 16 in the disk 9, a plurality of such pairs being arranged in the disk. By the fact that the end portions 15 of the pins 13 project each through an aperture 16 in the disk 9, the digit drum 1 and the gear wheel 2 become locked relatively to one another against a turning movement.

To permit loosening of the digit drum and the gear wheel from one another for a relative turning movement, the pins 13 will have to be moved in to an extent such that the outer portions 15 will be disengaged from the apertures 16 in consideration in the disk 9. This may be effected by means of a fork-shaped tool 17, the shanks IS, 19 of which have pins 2% fitting into the apertures 16 arranged thereon. The length of the pins equals the thickness of the disk h. By introducing the pins 20 of the tool 37 (FIG. 2) so that the portions 15 are brought out of engagement with the apertures 16, the digit drum '1 may be turned by a displacement of the tool in the radial plane of the disk 9 in the one or the other direction relatively to the gear wheel 2, until the portions 15 of the pins 13 snap into the adjacent pairs of apertures 36. The distance between the pairs of apertures is generally so adapted as to correspond to the displacement by one digit on the digit drum.

The advantages of the present invention are obvious. In a taxirneter calculating apparatus, for example, where the digit wheels are located close to one another, an adjustrnent to be undertaken with respect to the starting fare. Here, the calculating apparatus is zeroized, that is to say, the gear Wheel '2. or" the digit drums is disengaged from the respective driving member, and adjusting arms are caused to actuate the cam disks 7, so that the digit drums l are brought with their gear wheels into a definite starting position and are retained therein. This starting position is always the same for each unit with respect to the positions of the gear Wheel 2 and the pins l3, l5, inasmuch as it is determined by the zeroizing heart 7, which is rigidly arranged relatively to the gear wheel 2. After that, the shanks of the tool 17 are introduced into the space between two di it drums, and are preferably caused to bear on some guiding means adapted to center the shanks lit, 1%, whereupon the pins are introduced through a sidewise displacement of the tool toward the digit drum to be adjusted, into that pair of apertures, in which the portions 15 of the pins 13 are located and move in the same. After that, a displacement of the tool i7 is undertaken in the desired direction, as indicated above, in connection with which the digit drum, when the portions 15 snap into the adjacent pairs of apertures, will assume another angular position elatively to the gear Wheel thereof, that is to say, so that in the zeroizing or starting adjustment of the calculating apparatus a digit other than the previous one will be visible in the indicating opening of the casing of the calculating apparatus. if an adjustment of the digit drum to a digit, which is not an adjacent one, is desired, the above-named procedure will have to be repeated, until the desired digit has appeared. Through an arrangement according to the invention, an unauthorized adjustment of the digit drum is avoided by the fact that the outer portions 15 of the pins 13 are accessible in the space between the digit wheels, and that two pins will have to be pressed in at the same time, by reason of which an adjustment is very difiicult to undertake except by a tool of the type in consideration.

The invention is obviously not restricted to drums or disks provided with digits, inasmuch as any other signs may be considered. The tool described above to eflect the shifting or adjusting operation may of course be varied in different ways within the scope of the inven tion, and may of course, if desired, be built together with the calculating apparatus.

What is claimed is:

1. A locking device for the adjustment of digit wheels and'the like comprising a hub adapted to be fixed on a shaft of a calculating apparatus, a disc rotatably mounted on said hub, 21 digit drum carried by said disc, a gear wheel mounted on said hub in spaced relation to said digit drum, a bushing on said hub between said disc and said gear Wheel, means securing said gear Wheel to said bushing, and means releasably engageable with said disc to prevent rotation thereof relative to said gear wheel.

2. A locking device as defined in claim 1 wherein said disc includes portions defining a plurality of circumferentially spaced openings therein in adjacent coaxial relation to said hub, said bushing having portions defining a pair of diametrically opposed bores therein adapted to be aligned with a pair of diametrically opposed open ings in said disc, said means to prevent rotation of said disc relative to said gear wheel comprising a pin disposed in the bores in said bushing and extending into the openings in said disc, spring means in the bores in said bushing to bias said pins into the openings in said disc, and means engageable with said disc to disengage said pins from the openings therein and operable to eifect relative rotation between said disc and said gear wheel.

3. A locking device as defined in claim 2 wherein said means engageable with said disc to disengage the said pins from the openings therein comprises a fork-shaped tool having a pair of parallel shanks, a pin extending perpendicularly from each of said shanks adapted to be inserted into the openings in said disc and of a length equal to the thickness of said disc, said pins spaced a distance equal to the distance between diametricaliy opposed pairs of openings in said disc.

References Cited in the file of this patent UNITED STATES PATENTS 2,181,260 Bliss Nov. 2s, 1939 20 2,770,418 Hedges Nov. 13, 1956 2,992,775 Luscher July 18, 1961 

1. A LOCKING DEVICE FOR THE ADJUSTMENT OF DIGIT WHEELS AND THE LIKE COMPRISING A HUB ADAPTED TO BE FIXED ON A SHAFT OF A CALCULATING APPARATUS, A DISC ROTATABLY MOUNTED ON SAID HUB, A DIGIT DRUM CARRIED BY SAID DISC, A GEAR WHEEL MOUNTED ON SAID HUB IN SPACED RELATION TO SAID DIGIT DRUM, A BUSHING ON SAID HUB BETWEEN SIAD DISC AND SAID GEAR WHEEL, MEANS SECURING SAID GEAR WHEEL TO SAID BUSHING, AND MEANS RELEASABLY ENGAGEABLE WITH SAID DISC TO PREVENT ROTATION THEREOF RELATIVE TO SAID GEAR WHEEL. 